中国科学技术大学姜政课题组近日研究了，一维共价有机框架中孔壁上的氧还原反应内/外催化位点。相关论文于2024年12月3日发表在《德国应用化学》杂志上。

据介绍，孔通道对催化体系的传质起着决定性的作用。然而，由于很难在孔壁内或孔壁外构建锚定位点，因此孔壁内外催化位点的位置对性能的影响，之前仍未得到过充分研究。

该研究用具有精确锚定活性位点的一维共价有机框架（COFs），探讨了通道对典型氧还原反应（ORR）催化的影响。电催化评价表明，与锚定在通道外部的位点相比，位于通道内部的单个Pt位点表现出更高的动力学活性。

原位光谱分析表明，Pt-Cl断裂的局部重建和电位诱导的阴离子转移，在通道内更有效地发生。在ORR过程中，通道内活性位点优越的阴离子转运性和动力学活性，也比通道外活性位点更有利于*OH的脱附。

该研究结果为多相多孔催化剂活性位点的设计提供了策略。

附：英文原文

Title: In/Outside Catalytic Sites of the Pore Walls in One-Dimensional Covalent Organic Frameworks for Oxygen Reduction Reaction

Author: Shuai Yang, Zejin He, Xuewen Li, Bingbao Mei, Yifan Huang, Qing Xu, Zheng Jiang

Issue&Volume: 2024-12-03

Abstract: Pore channels play a decisive for mass transport in catalytic systems. However, the influences of the location of catalytic sites inside or outside of the pore walls on the performance were still under-explored due, because it is difficult to construct sites anchored in or outside of pore walls. Herein, one-dimensional covalent organic frameworks (COFs) with precisely anchored active sites were used to explore the effects of channels on a typical oxygen reduction reaction (ORR) catalysis. Electrocatalytic evaluations showed that single Pt sites located inside of the channels exhibited higher kinetic activity compared to those anchored outside. The in situ spectroscopic analysis revealed that local reconstruction of Pt–Cl breaking and potential-induced anion transport occurred more effectively inside the channels. The superior anion transportability and kinetic activity of the inside-channel active sites also facilitated *OH desorption during the ORR process outperforming their outside-channel counterparts. The results of this study provide strategies for designing active sites in porous catalysts for heterogeneous catalysis.

DOI: 10.1002/anie.202418347

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202418347